The present invention relates to the field of ignitor plugs for pyrotechnical devices.
The present invention is particularly, but not exclusively, applicable to grenades for hand launching or for use with mechanical launch means, and regardless of the function of such grenades, be they explosive, smoke-generating, illuminating, or a combination thereof.
Numerous documents relating to ignitor plugs have already been published.
Reference can be made for example, to documents FR-A-2 338 478, FR-A-2 354 506, and FR-A-2 428 233.
Document FR-A-2 686 688 describes a delay ignitor plug for a pyrotechnical device as shown in accompanying FIG. 1 that comprises a body 4 fitted with a control mechanism comprising a trigger lever 1 and a percussion mechanism 28 co-operating with a primary pyrotechnical module 5, 3, 9, 13 suitable for initiating the charge 19 of the associated device and axially displaceable in the body towards the main charge, means 2 for holding the primary pyrotechnical module 5 axially spaced apart from the main charge 19, and a screen 12a, 15 interposed between the main charge and the primary pyrotechnical module.
More precisely, in document FR-A-2 686 688, the means 2 for holding the primary pyrotechnical module 5 spaced axially apart from the main charge 19 are means that are purely mechanical, being actuated by the trigger lever 1.
Still more precisely, in document FR-A-2 686 688, the means for holding the pyrotechnical module 5 spaced axially apart from the main charge 19 comprise a clip 2 housed in the body 4 of the plug and engaged with the primary pyrotechnical module 5, the trigger lever 1 having a member 1a for extracting the clip during release of the trigger lever 1 relative to the body of said plug.
That known device shown in FIG. 1 operates essentially as follows.
To initiate the system, a pin 25 is extracted from the grenade by a, combined twist and pull action. The grenade is then thrown. Since the trigger lever 1 is no longer held in its locked position, elastic force from a spring 22 acts via a striker 24 to pivot the lever 1. After turning through about 30xc2x0, the finger 1a of the trigger lever 1 presses against the clip 2 and begins to extract it. During the next stage of lever pivoting, the striker 24 escapes and strikes the cap 3, the clip 2 still not being released from the delay primary pyrotechnical module 5. By inertia, the trigger lever 1 terminates its pivoting and releases itself from the body 4, taking the clip 2 with it, thereby unlocking the delay primary pyrotechnical module 5. Since this module is still subjected to the thrust from the striker 24 in association with the spring 22, the delay primary pyrotechnical module 5 is moved in translation, thus displacing the screen 12a, so that the solid element 12a of a cup 12 comes to the bottom of a cell 29 in a cup 18. A microdetonator 13 is then in position to initiate detonation by a radial effect.
An object of the present invention is to provide a novel, improved ignitor plug.
This object is achieved in a first aspect of the present invention by an ignitor plug for a pyrotechnical device, in particular a grenade for hand or mechanical launching, the device comprising a body fitted with a control mechanism comprising a trigger lever and a percussion mechanism co-operating with a primary pyrotechnical module for initiating the charge of the associated device, the plug being characterized by the fact that it further comprises a latch which engages the lever in the storage position to prevent free displacement of the trigger lever towards its release position, the latch being so shaped that during initial operation of the ignitor plug it requires the lever to be moved initially in the opposite direction to that required for releasing the percussion mechanism in order to disengage the latch from the trigger lever.
The person skilled in the art will understand that the structure as proposed in this way makes it possible to guarantee that the device is entirely reliable by preventing any non-authorized untimely firing.
According to an advantageous characteristic of the present invention, the latch is urged resiliently towards a release position where it is disengaged from the lever.
According to another advantageous characteristic of the present invention, the latch is itself held initially in an initial safe position by at least two mechanical blocking means, such that release of the latch requires both of these blocking means to be manipulated.
According to another advantageous characteristic of the present invention, one of the latch blocking means is formed by the trigger lever.
According to another advantageous characteristic of the present invention, one of the latch blocking means is formed by a pin.
According to another advantageous characteristic of the present invention, the primary pyrotechnical module is axially displaceable inside the body towards the main charge, and mechanical means hold the primary pyrotechnical module spaced axially away from the main charge in an initial, safe position, the plug being characterized in that the means for holding the primary pyrotechnical module axially apart from the main charge comprise the latch urged resiliently away from an initial, safe position in which the latch interferes with the travel path of the primary pyrotechnical module to prevent it from moving towards the main charge, towards a release position in which the latch lies off the travel path of the primary pyrotechnical module.
The above-specified object is achieved in a second aspect of the present invention by an ignitor plug for a pyrotechnical device, in particular a grenade for hand or mechanical launching, the device comprising a body fitted with a control mechanism comprising a trigger lever and a percussion mechanism co-operating with a primary pyrotechnical module for initiating the charge of the associated device and axially displaceable inside the body towards the main charge, and mechanical means for holding the primary pyrotechnical module spaced axially away from the main charge in an initial, safe position, characterized in that the means for holding the primary pyrotechnical module axially apart from the main charge comprise the latch urged resiliently away from an initial, safe position in which the latch interferes with the travel path of the primary pyrotechnical module to prevent it from moving towards the main charge, towards a release position in which the latch lies off the travel path of the primary pyrotechnical module, the latch being itself initially held in an initial, safe position by at least two mechanical blocking means such that release of the latch requires both of the blocking means to be manipulated.
According to an advantageous characteristic of the invention, the means for holding the primary pyrotechnical module axially spaced apart from the main charge further comprise a clip received in the body of the plug and initially engaged with the primary pyrotechnical module, the clip being provided with means suitable for co-operating with the trigger lever to act during release of the trigger lever to cause the clip to be extracted from the body of said plug.